Physics after Prom

Last weekend was prom. After prom, my friends and I rented a suite at Embassy Suites for the afterparty. In the picture we took outside of the hotel, you can see a bright spot of light on the "M" in Embassy Suites. This is light reflecting off of the metallic surface. The metal had a reflective coating that caused it to reflect light by acting like a mirror. When the light from the camera, the lights, and surrounding car headlights struck that "M," it hit the surface at an angle of incidence. It then reflects to your eyes at an angle of reflection, which is always equal to the angle of incidence.

Physics at a Party

Last weekend, our group of friends celebrated Adrian's birthday with a party at the Hilton. At night, we went on thttp://www.blogger.com/post-create.g?blogID=6965819012876089579
Blogger: Physics at Iolani - Create Posthe beach for a walk after dinner. Being the nerd that I unfortunately I am, I noticed how the waves at the beach are genuinely waves. If you observe the motion of the ocean, it looks like each strip of water is moving up and down from the horizon to the shore. However, this is in fact not the case. The waves are caused by vibrations in the tides. Each particle of water moves up and down with the motion traveling through the water such that the water goes up and down toward the shore in a successive pattern. This pattern is mirrored in many other types of waves, such as sound waves.

Physics in Drivers Ed

During Spring Break, I took Driver's Ed at Accurate Driving. It was a funny class that got a bit boring at times. A major theme of the class was that it is really bad not to wear your seatbelt. Glenn kept telling us that refusal to wear seatbelts makes drivers and passengers "MAKE! DIE! DEAD AT THE SCENE!" If you think about it, the world of physics leaves you with a perfect explanation as to why seatbelts are a good thing. Without seatbelts, the human body has a lot of inertia after a crash. When you crash, your body is in motion and will want to stay in motion. This inertia can lead you to smash into the dashboard or worse, the windshield. When your body smashes into one of these things at 50 mph, the force will jolt through your body and smash your brain into your skull and your internal organs into your ribcage and stomach lining. This leads to internal bleeding, septic shock, and permanent brain damage. However, when you are wearing a seatbelt, the belt prevents you from racing forward and absorbs the force. Thats good physics.

Physics in the Car

A couple weeks ago, Jordan, John, Jon, Adrian, Robert, and I went to the California Pizza Kitchen in Waikiki. We were all at John's house before that. Jordan was the only one who could drive, so all 6 of us climbed into his car. As a result of the order of calling seats, Adrian had to sit on Robert's lap in the backseat. Partially because we were all clamoring the entire car ride, Jordan was driving a little jumpy driving. Whenever he braked suddenly, Adrian would shoot forward. This can be explained through the physics concepts of inertia and momentum. Because Robert was moving with the car, he had inertia and wanted to stay in motion. When the car lurched to a stop, he kept moving. Because Adrian was inhibiting his course of motion, Robert was unable to move forward. Thus, his momentum, which was his moving force was transferred to Adrian. Therefore, Adrian lurched forward as the car lurched to a stop. (Photo credit: Jordan Rubio)

Powering Up Obama

While I was in New York last May for Economics Challenge nationals, there was a lot of hype over the about-to-be-crowned then nominee Barack Obama. While we were walking around in the city, we noticed that many buildings had electronic newsreels snaking around the ground floor. The pictured reel features an "Angry Obama." Like almost everything in New York City, this reel is powered by electricity. Electricity is created by a flow of electrons carrying electric energy. In order for electricity to power devices, there needs to be circuit connecting the device to a battery or some other electron generator. The circuit should be made of conductive material and must be continuous in order to allow the electrons to travel through the device. (Photo Credit: Leslie Kawano)

The Physics of Tubing

Every summer, I visit my grandmother and her boyfriend in California. They live in a small town in Northern California on a lake. They own a speedboat that they keep on the lake. Whenever I visit them in the summer, I go tubing on their boat. The above picture is from the summer before sophomore year. It is quite fun. When I tube, I lie down on a tube attached by a sixty foot rope to the back of the boat, which zooms around the lake at speeds approaching 45 mph. The rope creates an angle of about 30 degrees above the horizontal. Thus, when the boat pulls the tube, it exerts a force roughly equivalent to cos 30 X mass of me and tube X g. The weight of the tube with me on it was probably equal to 50 kilograms. This means that the boat exerts 424 Newtons of force as it pulls me. When I tube, I try to steer the tube outside of the wake when the boat makes sharp turns. When this happens, I shift my weight such that the tube leans to one side. It then speeds up. This is the equivalent of a car making a banked turn. When the tube leans over, it reduces friction by theta, which allows the tube to move faster.

The Physics of Airsoft

Every long weekend, my friends and I like to play Airsoft. Similar to paintball but much cooler, Airsoft is a game in which guys use replicas of assault rifles to shoot bbs at each other in military skirmish games. We play at an Airsoft place at Kaneohe Marine Corps Base. We play in a variety of fields, such as grasslands, forest, and close quarter battle fields. An Airsoft gun is an example of several physics concepts. My gun, and SR 16 M4 Carbine shoots bbs at upwards of 380 feet per second. As the bbs fly, they become a projectile, eventually hitting the ground unless they hit a person or bunker due to gravity. Although the bbs are small and light (0.20 grams), it stings to be shot by one. This is because they are traveling at a high velocity. Some people, like Preston, prefer to use 0.25 gram bbs. Theses bbs go a little slower as they resist the force of the gun more, but they go in a straighter path since they are less susceptible to air resistance. They also hurt more on impact as they weigh 25% more than 0.20 gram bbs. (Photo Credit: Robert Moran)

Center of Human Masses

Last week Friday after school, my friends and I were chilling at our benches in Weinberg. For some reason, Misha, Meatloaf (Jared), Dae (Jon), and me decided to try and see how good we could get at balancing on each other. After a few epic fails, Misha would jump on Meatloaf and I would jump on Misha and none of us would tip over. It was pretty fun. I was pretty surprised that Meatloaf was able to sustain roughly 250 pounds on his back without dying (although, judging by his facial expression in the picture, he came rather close). I then remembered learning about center of mass in physics (actually, I was absent that day). The center of mass of an object is the point at which there is an equal amount of mass on either side such that the object is at equilibrium. Looking at the picture, the center of mass on the x-axis was probably just to the right of Misha's shoulders. If you look down in the picture from that point, it is right near Meatloaf's feet. This means that the equilibrium point was just over a stable point that was supporting all of us. This explains why we did not tip over since the balance point of the three of us was being directly supported by Meatloaf's legs and feet. (Photo credit: Bree Chun)

This picture was taken while I was in New York City for the the Economics Challenge last May. It was taken in a pub-type restaurant in Greenwich Village. It features a game of darts between Braxton Sato and myself. The dart in the outer ring of the bullseye was mine; the dart on the fringe of the board was Braxton's. Unfortunately, we were unable to continue our game. Darts is a game contingent on the laws of physics. When a dart hits the board and pierces it without falling off, the laws of momentum are at work. When the dart strikes the board, it has a momentum equal to its mass multiplied by its velocity. However, when the dart strikes board, the board exerts force on the dart over a period of time. The time multiplied by the average force is called an impulse. The impulse is also the change in momentum. The board exerts a force on the dart, continuously decreasing its momentum, and consequentially, its velocity. This continues until the velocity of the dart is 0. The dart does not bounce off of the board because by the time its forward momentum finally equals 0, it is so far submerged in the board that it is does not bounce off.

Friction: Trick or Treat?

Last Friday, in addition to being homecoming was Halloween. After the game, eating, Ho'olauleia (sp?), and the Burning of the I, my friends and I went trick or treating in Kahala. Outside of the mall, we there was a Longs shopping cart stuck in the mud. Robert climbed into the cart and I tried to pull him out of the grass. We truly are geniuses. However, when I tried pulling the cart wouldn't slide and Robert almost fell out. I was confused. I thought that when I pull an object, the object should move. However, I then remembered friction. Friction occurs when there is a force between two objects preventing them from being slid against one another. The rubber wheels and the dried mud clung together, thus making pulling the cart very difficult. When Robert went in the cart, friction increased. Friction is equal to normal force times the coefficient of friction. Since the coefficient of friction is constant, Robert's 140 pounds increased normal force by approximately 450 Newtons. Thus, our antics were impeded by the phun of friction.

Reflections of the First Quarter of Physics

Physics has been completely different from my expectations of it. I thought that physics would be a really easy course that was conceptual, and not mathematic in nature. I built up these expectations through conversations with former physics students and my own notions about what physics was. To be honest, this was kind of disappointing to me. I have never been a science person, however, I really enjoyed Science 7 and Science 8. I dislike most science classes because they tend to examine physical phenomena in such a mathematical, technical manner that the phenomena themselves become so detached from what we are learning. However, in Science 7 and Science 8, we learned about how things worked, not the formulae that served as mathematical proofs as to why things worked the way that they did. I thought that physics would be focused on learning about the conceptual nature of the laws of physics and how they manifest themselves in the world. Instead, physics seems like basically a harder version of any math course that I have taken at Iolani. Instead of learning why elevators fall in the way that they do, it seems like we just use that example in order to apply mathematical formulae. I don't really understand why we learning that kind of thing. The way I see it, we take math courses every semester at Iolani, so why should physics just be another math course? Except for the lab about getting the ball in the cup, it seems like most of the labs are basically extended math problems in which we must collect the data for the problem, as opposed to just being given it. I wish labs were more like they were in Science 7, Science 8, and even Biology, in which their purpose was to give us hands-on ways of learning and examining the things that we are learning. However, physics has definitely had some very good elements. Unlike most classes, physics can be laid-back and fun. I really like the atmosphere of the classroom, and coming to physics is one of the better parts of my school day. In terms of grades, I am not doing as well as I want to be doing. I am having a hard time incorporating trigonometry (which I haven't taken yet) into the course. I also tend to work sloppily and take more short cuts than is permissible, which seems to be particularly damaging in physics. I think the class might be easier if more time was spent devoted to being taught how to do the problems multiple times.

Newton's Third Law on the Campaign Trail

Yesterday, some of my friends and I waved signs for John McCain, fulfilling part of our APUSH campaigning requirement. We walked around the area near Ala Moana and eagerly waved our signs. However, some angry liberals felt the need to flip us off and yell "#$&% YOU!" This is an example of Newton's Third Law. This law posits that for every action there is an equal and opposite reaction. For example, If I push Preston to the left with 89 newtons, Preston would be pushing me to the right by 89 Newtons. While we were campaigning, angry bird-flipping was equal in severity but opposite in meaning to our friendly waves, shakas, and signs. Who knew that campaigning would turn into a physics lesson?

The Hang Time of My Golf Drive

I love to play golf. Golf is a sport that combines the physical precision that the best of sports require with the leisurely pleasure that any activity should have. Unfortunately, I do not get to golf very often, and thus, I am not a wonderful golfer. When I golf with him, my grandpa keeps a distance finder to measure all of our drives. My best drive thus far has been 205 yards. I am going to use the knowledge in my physics textbook to explain why my arms, which are completely incapable of throwing the ball 205 yards, are able to drive it that far. The answer lies in the leverage that I am able to utilize when I swing the golf club. Because of centrifugal force, the club extended from hands is able to swing much further and faster than my arms do when they are swinging the club. The club is light overall, and yet has a heavy chunk of metal which hits the ball. Therefore, when I hit the ball with a relatively slow, weak swing with a light club, the ball flies 205 yards because the swing multiplies the force of my swing on the club and when the heavy point smashes into the ball, the ball goes further than would be expected.

Acceleration Learned the Hard Way

This past week, my family flew in from California and had a reunion in Kailua. I was supposed to watch my baby cousin for about ten minutes and he was playing on the coffee table in the living room. We were playing a game of sorts in which he would drop a very large toy car and I would catch it immediately. However, after about 3 minutes, I forgot to catch the car and it fell on my toe. It hurt and I may have taught my cousin a word for which he might get in trouble if he repeats. This got me thinking. Why would the car hurt after it fell on my toe but not when it fell on my hand when I caught it? I looked through my physics textbook and discovered that falling objects fall at 9.8 meters per second squared. Thus, it hurt more when it fell on my toe because it was airborne longer, meaning that it was going much faster when it hit my toe compared to when it hit my hand. I also figured out that velocity has a positive correlation with force, accounting for the pain felt when the car hit my toe.